The present invention relates to an aerosol delivery apparatus, and in particular, to an aerosol medication delivery apparatus having a narrow orifice.
Aerosol medication delivery systems are used, in general, to administer medication in aerosol form to the lungs of a user. For example, some systems use a pressurized metered-dose inhaler (pMDI), which typically includes a container in which the medication particles are stored under pressure, and an actuator used to dispense the medication from the container. In other systems, a holding chamber is connected to one of the container or actuator, as shown for example in U.S. Pat. No. 6,293,279, assigned to Trudell Medical International, and which is hereby incorporated herein by reference. The holding chamber reduces the need for the user to coordinate activation of the pMDI canister with inhalation, helps reduce the delivery of nonrespirable medication particles from the canister, and helps reduce the impaction of medication particles in the user's oropharnyx and upper airway. In some configurations, shown for example in the U.S. Pat. Nos. 6,293,279 and 5,881,718, the apparatus can be provided with one or both of an inhalation and exhalation valve(s) at an output end of the chamber. The output end is typically configured with a mouthpiece, which is received in the mouth of the user, or with a mask, which is placed over the mouth and nose of the user.
Users of the aforementioned devices often suffer from various bronchial ailments that can reduce lung capacity and output, which problems can be exacerbated with young children and domestic cats and dogs. Many of these devices, however, are not especially suited for users with low tidal volumes, such as neonatals. In particular, such devices typically have an orifice at the output end of the holding chamber that is greater than 78 mm2. Such relatively large openings may not produce the sweeping force necessary to draw aerosol out of a chamber with low tidal volumes, especially when the device is configured with inhalation/exhalation valves. As used herein, the word “user” includes humans and animals, including domestic cats and dogs.